Compression moulding apparatus, methods and item

ABSTRACT

An apparatus comprises a molding unit having a punch and a mold cavity movable along a path between an open position in which said punch and said mold cavity are distanced apart from each other to receive a dose of plastics therebetween, and a closed position in which said punch and said mold cavity interact to form an item by pressing said dose, said punch being kept not above said cavity along said path.

CROSS REFERENCE TO RELATED APPLICATIONS

This is a divisional of U.S. application Ser. No. 10/576,870, filed Apr.21, 2006, which is the US national phase of international applicationPCT/EP2004/011968 filed Oct. 22, 2004, which designated the U.S. andclaims benefit of IT MO2003A000289 filed Oct. 23, 2003, eachincorporated herein by reference in its entirety.

The invention relates to apparatuses and methods for producing items,for example for compression moulding items made of plastics, such ascaps for bottles and containers. The invention further relates to anitem made of plastic materials.

U.S. Pat. No. 5,807,592 discloses an apparatus for producing caps havinga plurality of moulding units mounted on a carousel which rotates aroundan axis. Each moulding unit includes a mould cavity in which a dose ofplastic material in a fluid or semifluid state is fed and a punch whichinteracts with the cavity so as to shape the dose according to thedesired shape of the cap. Each mould cavity and the corresponding punchare movable between an open position in which they are distanced apartto receive the dose therebetween and a closed position in which theyinteract to form the cap from the dose by compression moulding.

Plastics is fed by an extruder and removed therefrom by means of removalelements fixed to the edge of a pan rotatable around a further axisparallel to the axis of the carousel. Each removal element removes fromthe extruder a dose of plastics, which due to its viscosity remainsattached to the corresponding removal element.

The removal element carrying the dose rotates together with the pan andreaches a position above an underlying cavity, which is distanced apartfrom the corresponding punch. An air blast detaches from the removalelement the dose, which falls in the underlying cavity where it will beformed.

A defect of the apparatus disclosed in U.S. Pat. No. 5,807,592 is thatthe lower portion of the dose which contacts the cavity when fallingthereon is cooled more quickly than the adjacent portions of the dose.Therefore, the viscosity of the plastic dose in its lower portionincreases more than in the adjacent portions of the dose, which preventsthe material of the dose from flowing freely inside the moulding unitand uniformly filling the space between the cavity and the punch.

Furthermore, due to non-uniform cooling of the dose, a cap is obtainedin which the zones that cooled earlier have an appearance and astructure different from the zones that cooled later. Since the zoneswhich cool first are located on the outer surface of the cap which is incontact with the cavity, such zones are unpleasantly visible by aconsumer when the cap is in use.

U.S. Pat. No. 4,943,405 discloses an apparatus for manufacturingcompression moulded articles having an annular cross-section, in which amould cavity is arranged beneath an extruder. On opening of a closingelement of the extruder, a stream of heated thermoplastic material withan annular cross-section flows from the orifice of the die and issupported by an intermediate support. The intermediate support extendsinside of the mould cavity and is movable therein between an extendedposition, in which the intermediate support is close to the extruder toreceive the thermoplastic material therefrom, and a retracted positionin which the intermediate support retracts below the mould cavity so asto define a bottom part thereof and the thermoplastic material is formedaccording to a desired shape.

A defect of the apparatus disclosed in U.S. Pat. No. 4,943,405 is that acomplicated structure is disclosed, which requires that the intermediatesupport be associated to an actuating device capable of functioning intothe narrow region of the cavity.

Furthermore, due to mechanical wear of the intermediate support and/orthe cavity, the heated thermoplastic material may penetrate in the spacebetween the side walls of the mould cavity and the intermediate supportwhich defines the bottom part of the cavity. If this happens, adefective line is formed on the finished article, the defective lineprotruding from the body of the article.

An object of the invention is to improve the apparatuses and methods forproducing items, especially for compression moulding plastics items.

A further object of the invention is to provide apparatuses and methodsby means of which plastics items having a good appearance and relativelyuniform mechanical, physical and chemical properties may be obtained.

A still further object of the invention is to provide apparatuses havinga moulding unit in which a plastics item is produced, the moulding unitbeing of simplified construction.

According to a first aspect of the invention, there is provided anapparatus, comprising a moulding unit having a punch and a mould cavitymovable along a path between an open position in which said punch andsaid mould cavity are distanced apart from each other to receive a doseof plastics therebetween, and a closed position in which said punch andsaid mould cavity interact to form an item by pressing said dose, saidpunch being kept not above said cavity along said path.

In one embodiment, there is provided a supporting arrangement extendingexternally of said mould cavity for supporting said dose between saidpunch and said mould cavity in said open position.

This allows the dose of plastics to be kept between the punch and themould cavity in the open position irrespective of the position of thepunch relative to the mould cavity.

In particular, the punch may be placed under the cavity, or the punchand the cavity may be placed on a common horizontal plane, while thedose is kept therebetween.

According to a second aspect of the invention, there is provided anapparatus, comprising a moulding unit having a punch and a mould cavitymovable between an open position in which said punch and said mouldcavity are distanced apart from each other to receive a dose of plasticstherebetween, and a closed position in which said punch and said mouldcavity interact to form an item by pressing said dose, a supportingarrangement extending externally of said mould cavity for supportingsaid dose between said punch and said mould cavity in said open positionand oscillatable by a movable cam arrangement.

Owing to this aspect of the invention, it is possible to keep theplastics dose out of contact with the cavity walls until immediatelybefore the punch enters the cavity.

Thus, undesirably precocious cooling of dose portions is avoided andeach dose maintains a substantially uniform density throughout itsvolume.

According to a third aspect of the invention, there is provided anapparatus, comprising a pair of rods for supporting a dose of plasticsbetween a punch and a mould cavity, said pair of rods being connected toa respective pair of levers hinged at a base body, each lever of saidpair of levers being connected to the other lever of said pair of leversby a connection rod.

According to a fourth aspect of the invention, there is provided anapparatus, comprising a moulding unit having a punch and a mould cavitymovable along an axis between an open position in which said punch andsaid mould cavity are distanced apart from each other to receive a doseof plastics therebetween, and a closed position in which said punch andsaid mould cavity interact to form an item by pressing said dose, asupporting arrangement for supporting said dose between said punch andsaid mould cavity and having a member oscillatable parallely to saidaxis.

According to a fifth aspect of the invention, there is provided anapparatus, comprising a moulding unit having a punch and a mould cavitymovable between an open position in which said punch and said mouldcavity are distanced apart from each other to receive a dose of plasticstherebetween, and a closed position in which said punch and said mouldcavity interact to form an item by pressing said dose, a supportingarrangement for supporting said dose between said punch and said mouldcavity and oscillatable by a gear device.

Owing to these aspects of the invention, support for the dose ofplastics may be provided in a particularly simple manner.

According to a sixth aspect of the invention, there is provided anapparatus, comprising a moulding unit having a punch and a mould cavitymovable along an axis between an open position in which said punch andsaid mould cavity are distanced apart from each other to receive a doseof plastics therebetween, and a closed position in which said punch andsaid mould cavity interact to form an item by pressing said dose, asupporting arrangement for supporting said dose between said punch andsaid mould cavity, said supporting arrangement comprising a supportingmember of porous material.

According to a seventh aspect of the invention, there is provided anapparatus, comprising a moulding unit having a punch and a mould cavitymovable along an axis between an open position in which said punch andsaid mould cavity are distanced apart from each other to receive a doseof plastics therebetween, and a closed position in which said punch andsaid mould cavity interact to form an item by pressing said dose, asupporting arrangement for supporting said dose between said punch andsaid mould cavity, said supporting arrangement comprising a tubularsupporting member having holes through which air can be injected towardsaid dose.

Owing to this aspect of the invention, it is possible to insufflate afluid, for example air, at a predetermined state (i.e. temperatureand/or pressure and/or humidity) so that the dose can be maintained at adesired state.

According to an eighth aspect of the invention, there is provided anapparatus, comprising a moulding unit having a punch and a mould cavitymovable along an axis between an open position in which said punch andsaid mould cavity are distanced apart from each other to receive a doseof plastics therebetween, and a closed position in which said punch andsaid mould cavity interact to form an item by pressing said dose, asupporting arrangement for supporting said dose between said punch andsaid mould cavity, said supporting arrangement comprising a supportingmember of thermally substantially non-conductive material.

Owing to this aspect, cooling of the dose is substantially avoided whencontact occurs between the dose and the supporting member.

According to a ninth aspect of the invention, there is provided anapparatus, comprising a moulding unit having a punch and a mould cavitymovable between an open position in which said punch and said mouldcavity are distanced apart from each other to receive a dose of plasticstherebetween, and a closed position in which said punch and said mouldcavity interact to form an item by pressing said dose, a dose-deliveringmouth of an extruder being interposed between said punch and saidmoulding cavity in said open position.

Owing to this aspect of the invention, it is no longer necessary toprovide a rotatable pan, or another transport arrangement, to transferthe dose of plastics from the extruder to the mould cavity. Constructionof the machine is therefore significantly simplified.

In one embodiment, a severing arrangement co-operates with thedose-delivering mouth so as to sever the dose from the extruder.

The severing arrangement can be mounted on the moulding unit.

The severing arrangement can be rotatable around a respective axis.

The severing arrangement may be driven by an independent motor unit.

The severing arrangement may be provided with a blade connected to asupporting member of a supporting arrangement, or with a knife mountedon the punch or the moulding cavity.

Owing to the severing arrangement, the dose may easily be detached fromthe extruder mouth and delivered to the moulding unit.

According to a tenth aspect of the invention, there is provided anapparatus, comprising a moulding unit having a punch and a mould cavitymovable between an open position in which said punch and said mouldcavity are distanced apart from each other and receive a plurality ofdoses of plastics therebetween, and a closed position in which saidpunch and said mould cavity interact to form an item by pressing saidplurality of doses.

Owing to this aspect of the invention, it is possible to manufactureitems of plastics made from two or more materials, or colours of thesame or different materials.

According to an eleventh aspect of the invention, there is provided amould compression item comprising a body formed from a plurality ofplastic materials having different properties and/or appearance from oneanother.

Thus, a mould compression item is obtained which is more attractive thanconventional mould compression items due to the combination of two ormore colours of the same material for the various doses.

It is also possible to provide a mould compression item having peculiarproperties due to the combination or juxtaposition of various materials.

According to a twelfth aspect of the invention, there is provided amethod, comprising delivering a plurality of doses of plastics to amoulding unit and pressing together said plurality of doses between apunch and a mould cavity.

This allows the new mould compression item to be easily manufactured.

According to a thirteenth aspect of the invention, there is provided anapparatus comprising a moulding unit having a punch and a mould cavityone of which serving as a receiving member for receiving a dose ofplastics in an open position, said moulding unit being movable along apath between said open position and a closed position in which saidpunch and said mould cavity interact to form an item by pressing saiddose, a channel system being provided to surround said receiving memberin said open position along said path.

In one embodiment, a transferring device is provided for transferringsaid dose from an extruder mouth to said moulding unit along a furtherpath, said transferring device being surrounded by a channel systemextending along said further path.

Owing to this aspect of the invention, it is possible to introduce aconditioning fluid into said channel system so as to keep said dose in adesired environment.

Thus, for example, temperature of the dose can be easily controlled.

In a fourteenth aspect of the invention, there is provided a method forcompression moulding of plastics items, comprising forming a dose ofplastics in a moulding unit by bringing together a punch and a mouldcavity, wherein before said bringing together, said dose is propelledtowards either said punch, or said mould cavity.

This allows to minimize the period of time in which the dose is kept incontact with the mould parts before the parts are brought together andform the item.

In a fifteenth aspect of the invention, there is provided an apparatus,comprising a pair of rods for supporting a dose of plastics between apunch and a mould cavity, said pair of rods being actuatable by a camarrangement having a first portion for driving said rods in adose-receiving position in which said dose is received above said rodsand a second portion for driving said rods in a dose-pinching positionin which said dose is pinched between said rods, said second portionbeing adjacent to said first portion.

In a sixteenth aspect of the invention, there is provided a method forcompression moulding of plastics items, comprising forming a dose ofplastics in a moulding unit by bringing together a punch and a mouldcavity, and further comprising, before said bringing together, restingsaid dose on a pair of rods, moving said rods close to one another so asto pinch said dose, and delivering said dose from said rods to saidmoulding unit, wherein between said resting and said moving the doseremains in contact with said rods.

Owing to the fifteenth and sixteenth aspects of the invention, the rodscan firmly hold the dose before delivering it to the moulding unit. Thedose, pinched by the rods, is prevented from reaching the moulding unitat an undesired time even if subjected to high accelerations.

In order that the invention may be clearly and completely disclosed,reference will now be made, by way of example, to the accompanyingdrawings, in which:

FIG. 1 is a plan view of an apparatus for compression moulding ofplastics caps;

FIGS. 2 to 4 are fragmentary views of a moulding unit of the apparatusof FIG. 1, in subsequent moulding steps;

FIGS. 5 to 7 are fragmentary views like FIGS. 2 to 4, showing a mouldingunit according to an alternative embodiment;

FIGS. 8 to 10 are fragmentary views like FIGS. 2 to 4, showing amoulding unit according to a further alternative embodiment;

FIG. 11 is a schematic, fragmentary side view of a supportingarrangement for supporting a dose of plastics material between amoulding cavity and a punch of the apparatus of FIG. 1;

FIG. 12 is a fragmentary, plan view of supporting members for supportinga dose of plastics material, in a dose-delivering configuration;

FIG. 13 is a front view of a cam actuating the supporting members ofFIG. 12, taken along the plane A-A of FIG. 12;

FIG. 14 is a view like FIG. 12, showing the supporting members in adose-receiving configuration;

FIG. 15 is a view like FIG. 13, taken along the plane B-B of FIG. 14;

FIGS. 16 to 18 are fragmentary, partially sectioned side views of amoulding unit provided with the supporting members of FIGS. 12 to 15;

FIG. 19 is a plan view of supporting members actuated by a gear device;

FIG. 20 is a fragmentary, front view of a moulding unit provided with atransferring device for transferring a plastics dose from an extrudermouth to a supporting arrangement;

FIG. 21 is a side view of the moulding unit of FIG. 20, in which thetransferring device has been removed for ease of understanding;

FIG. 22 is a view from above of the transferring device shown in FIG.20;

FIG. 23 is a view like FIG. 20, in which the transferring device rotatesaround an inclined axis;

FIG. 24 is a side view of the transferring device shown in FIG. 23;

FIG. 25 is a view like FIG. 24, showing a transferring device used totransfer doses of plastics material from an extruder mouth to alreadyformed caps, in order to form a sealing member thereon;

FIG. 26 is a front view of the transferring device of FIG. 25;

FIG. 27 is a partially sectioned, fragmentary side view of a mouldingunit cooperating with a severing arrangement to sever a dose of plasticsmaterial from an extruder;

FIG. 28 is a view like FIG. 27, showing a different embodiment of themoulding unit;

FIGS. 29 to 31 are fragmentary, partially sectioned side views of amoulding unit provided with a severing knife to sever the dose ofplastics material from the extruder;

FIGS. 32 to 35 are fragmentary, partially sectioned side views of amoulding unit having a punch movable along a horizontal axis, insubsequent moulding steps;

FIG. 36 is a perspective, schematic view of a supporting arrangementsupporting two doses of plastics;

FIG. 37 is a plan view of a supporting arrangement including two pairsof supporting members for supporting two doses of plastics material;

FIG. 38 is a perspective, schematic view of a supporting arrangementsupporting two doses of plastics, according to an alternativeembodiment;

FIG. 39 is a perspective view of a compression moulded screw cap madefrom two distinct kinds of plastics;

FIG. 40 is a schematic side view of a hinge closure made from two kindsof plastics; and

FIG. 41 is a schematic cross-section taken along the axis of acompression moulded screw cap made from two distinct kinds of plastics;

FIGS. 42 to 45 are fragmentary, partially sectioned side views of amoulding unit having rods for supporting a dose which are actuatedindependently of the mould cavity and the punch;

FIGS. 46 to 48 are fragmentary, partially sectioned side views of amoulding unit having rods fixed to a carousel;

FIGS. 49 and 50 are fragmentary, partially sectioned side views of amoulding unit in which a dose is pinched by a pair of supporting rods.

Within the context of the present description the expression “mouldcavity” has to be construed as meaning a cavity either of a mould in amoulding unit, or of a formed item in which a dose of plastics has to beinserted and subsequently compression moulded, for example when it isdesired to form a seal for a screw cap.

FIG. 1 shows an apparatus 1 for compression moulding plastics items,particularly plastics caps for bottles or containers. The apparatus 1includes a carousel 2 rotatable in the direction of the arrow X aroundan axis A and provided, in a peripheral region thereof, with a pluralityof moulding units 3. Each moulding unit 3 includes a mould cavity shapedaccording to the external geometry of the cap to be obtained and a punchreproducing the internal shape of the cap.

The mould cavity and the punch are movable between an open position inwhich they are distanced apart from each other to receive a dose ofplastics therebetween, and a closed position in which the punch and themould cavity interact to form the cap from the dose.

The dose is fed by an extruder 6 in a fluid or semifluid state andremoved from the extruder 6 by removal elements 7. The removal elements7 are fixed to the lower part of a circular plate 8 rotatable in thedirection of the arrow Y around a further axis parallel to the axis A. Astar-disc 9 is movable rigidly with the plate 8 and is located above theplate 8. The star-disc 9 is peripherally provided with a plurality ofrecesses 10 used to remove each cap from the corresponding mouldingunit.

Each removal element 7, when passing above the extruder 6, removes fromthe mouth of the extruder the dose, which remains adherent to theremoval element 7 due to the viscosity of the plastics. As the plate 8rotates, the removal element 7 carries the dose along a circular path Guntil the removal element 7 reaches a position in which it interactswith a moulding unit 3. The latter is in the open position, so as to becapable of receiving the dose from the corresponding removal element 7.

The dose is detached from the removal element 7 by an air blast andfalls onto an underlying supporting arrangement having a pair of rods 11arranged between the mould cavity and the punch. Simultaneously, the capformed in the moulding unit 3 during a previous working cycle is removedtherefrom by a respective recess 10 of the star-disc 9 and conveyedtowards an exit channel 12 along a path defined by guides 13, 14.

The structure of the star-disc 9 and of the rotatable plate 8 isdisclosed in detail in U.S. Pat. No. 5,807,592, which is herewithincorporated by reference.

The rods 11 are movable between a dose-receiving configuration in whichthe rods 11 are relatively close to each other to retain the dosefalling from the removal element 7, and a dose-delivering configurationin which the rods 11 are relatively distanced apart from each other todeliver the dose to the moulding unit 3.

In a further embodiment, which is not shown, an air blast is providedfor detaching the dose D from the removal element 7. The rods 11,actuated by a respective cam, grip the dose D attached to the removalelement 7 and remove therefrom the dose D.

After the dose has been delivered to the moulding unit 3, the punch andthe mould cavity reach the closed position so as to form the cap fromthe dose and stabilise its shape along the circular path C of thecarousel 2. Thereafter, the mould cavity and the punch open to allow thecap to be removed and a new working cycle begins.

A first channel segment 300 having a curved profile surrounds a portionof the carousel 2; the first channel segment 300 is stationary and has afirst inlet 301 through which the mould cavities 4 enter one after theother and a first outlet 302 from which the mould cavities 4 exit thefirst channel segment 300. At a delivering position W between the firstinlet 301 and the first outlet 302 the dose D is delivered by therotatable plate 8 to the rods 11.

A second channel segment 303 extends from a nozzle 73 of the extruder 6to the delivering position W around the rotatable plate 8. The secondchannel segment 303 has a second inlet 304 through which the removalelements 7 enter the second channel segment 303 one after the other anda second outlet 305 from which the removal elements correspondingly exitthe second channel segment 303.

The first channel segment 300 is provided with a third exit 306 throughwhich the removal elements 7 exit the first channel segment 300 afterdelivering the dose D at the delivering position W. The first channelsegment 300 and/or the second channel segment 303 may contain athermally controlled fluid by means of which temperature of the dose Dmay be kept above a predetermined limit to avoid solidification of thedose D.

Combination of the rods 11 and the first and second channel segments300, 303 ensures that the mould compressed items are deprived of anyunpleasantness and/or substantial disuniformities of structuralcomposition.

As shown in FIG. 2, the punch 5 can be located in the moulding unit 3below the mould cavity 4. The punch 5 is arranged at the top of a stem15 integral with the carousel 2.

A pair of levers 16 is associated with the punch 5, each lever 16supporting an end of a corresponding rod 11. A further pair of leverscan be provided on the side of the punch 5 opposite the side shown inFIG. 2. In this case, each end of the rod 11 is supported by arespective lever. In an alternative embodiment, only the two levers 16may be provided, supporting the rods 11 in a cantilever manner.

The levers 16 are mutually hinged at a point P. One of the levers 16 hasan appendage 17 carrying a roller 22.

The mould cavity 4 is fixed to the end of a further stem 18 movable withrespect to the carousel 2 towards, and away from, the punch 5. A cam 19is connected to the mould cavity 4, the cam 19 having the shape of anelongated element extending in the direction F of movement of the mouldcavity 4. The cam 19 has a rectilinear portion 20 adjacent to aninclined portion 21.

The mould cavity 4 and the punch 5 are shown in FIG. 2 in the openposition. The levers 16 are close one to the other, so as to drive therods 11 in the dose-receiving position and the dose D has just beendelivered to the rods 11.

The mould cavity 4 then starts moving towards the punch 5 as shown inFIG. 3 and reaches a position in which the inclined portion 21 of thecam 19 interacts with the roller 22. The cam 19 causes the levers 16 tooscillate around the point P, so that the rods 11 are moved apart fromeach other. The shape of the inclined portion 21 and the speed of themould cavity 4 are so chosen as to cause the levers 16 to open quickly.Thus, the dose D receives a strong thrust and is pushed upwards towardsthe mould cavity 4.

In the meantime, the mould cavity 4 continues moving towards the punch 5and, in the position shown in FIG. 4, starts interacting with the punch5 to shape the dose D. The rods 11 are kept distanced apart from eachother by the roller 22 engaging the rectilinear portion 20 of the cam19.

It is observed that the dose D contacts the rods 11 for a minimum time,which substantially avoids rapid cooling of the dose D and allows thedose D to uniformly cool when interacting with the punch 5 and the mouldcavity 4. Defects in the appearance of the cap due to non-uniformcooling of the dose D are therefore substantially avoided.

It is further observed that the levers 16 and the rods 11 extendexternally of the mould cavity 4. Thus, there is no need to adoptcomplicated supporting devices movable inside the mould cavity 4.

According to the alternative embodiment shown in FIGS. 5 to 7, the cam19 is fixed to the carousel 2. The stem 15 which supports the punch 5,located below the mould cavity 4, is slidable in a bushing 23 mounted onthe carousel 2. Thus, the punch 5 moves in the direction F towards, andaway from, the mould cavity 4. The latter is connected to the carousel2.

FIG. 5 shows the punch 5 and the mould cavity 4 in the open position,with the dose D resting on the rods 11. When the punch 5 moves towardsthe mould cavity 4, as shown in FIG. 6, the roller 22 interacts with theinclined portion 21 of the cam 19, which causes the levers 16 tosuddenly oscillate around the point P, thereby projecting the dose Dtowards the mould cavity 4. The levers 16 are thereafter kept open bymeans of the roller 22 engaging the rectilinear portion 20 of the cam19, thereby allowing the punch 5 to interact with the mould cavity 4 andform the cap from the dose D. This is shown in FIG. 7. In a furtheralternative embodiment shown in FIGS. 8 to 10, the mould cavity 4 ispositioned below the punch 5. The levers 16 are connected to the mouldcavity 4 and are mutually hinged at point P. The mould cavity 4 isstationary with respect to the carousel 2.

The punch 5 is fixed to the stem 15, which is slidingly movable withrespect to the carousel 2. Thus, the punch 5 can move in the direction Ftowards, and away from, the mould cavity 4.

The cam 19 is fixed to a side extension 24 of the punch 5.

FIG. 8 shows the moulding unit 3 in the open position in which the punch5 is distanced apart from the mould cavity 4.

The levers 16 are close to one another so that the rods 11, extendingabove the mould cavity 4, can receive and retain the dose D.

When the punch 5 starts moving towards the mould cavity 4, as shown inFIG. 9, the inclined portion 21 of the cam 19 contacts the roller 22 andcauses the levers 16 to open by oscillating around the point P. Thequick movement of the levers 16 pushes the dose D towards the punch 5.

The levers 16 are then kept open by the roller 22 interacting with therectilinear portion 21 of the cam 19, thereby allowing the punch 5 topenetrate inside the mould cavity 4, as shown in FIG. 10, and shape thedose D into a cap.

In a further embodiment, shown in FIGS. 42 to 45, the levers 16 aresupported by a holder 52 which is independent of the punch 5 and themould cavity 4. The holder 52 is slidable along the direction F by meansof a non-shown actuating device, for example a cam. The mould cavity 4,positioned below the rods mounted on the levers 16, is also slidinglymovable along the direction F, whereas the punch 5 is stationary withrespect to the carousel 2. However, the mould cavity 4 and the holder 52are actuated independently one of another.

As shown in FIG. 42, the moulding unit 3 is initially in an openposition, in which the mould cavity 4 is distanced apart from the punch5. The holder 52 is in its lowermost position, close to the mould cavity4. A dose D is then delivered onto the rods mounted on the levers 16.

At this point, the holder 52 is actuated upwards, by means of itsrespective actuating device, and brings the levers 16, the rods and thedose D towards the punch 5, as shown in FIG. 43. The mould cavity 4 isstill stationary on the carousel 2. When moving towards the punch 5, theholder 52 reaches a position, shown in FIG. 44, in which the roller 22contacts the cam 19 that is integral with the carousel 2. The cam 19rotates the levers 16 around the hinge-point P and the rods are movedaway one from another, thereby propelling the dose D against the punch5. In the meanwhile, the mould cavity 4 has been moved closer to thepunch 5 so as to receive the dose D therebetween and then shape the doseD into a cap, as shown in FIG. 45.

By actuating the mould cavity 4 and the levers 16 independently one ofanother, the dose D can be released by the rods as late as possible. Itis thus possible to prevent the dose D from contacting the mould cavity4 and/or the punch 5 before being compressed, which would undesirablycool the dose D.

It is noted that the independently actuatable rods disclosed inconnection with FIGS. 42 to 45 can be used in combination with anymutual arrangement of the punch and mould cavity.

In a still further embodiment, shown in FIGS. 46 to 48, the levers 16are supported by an arm 53 which is integral with the carousel 2. Thearm 53 and the levers 16 are so configured as to allow the mould cavity4 to pass between two facing pairs of levers 16 without interfering withthem.

The mould cavity 4 is slidable in the direction F so as to move awayfrom, and close to, the punch 5. In an initial configuration, themoulding unit 3 is in its open position in which the mould cavity 4 isdistanced apart from the punch 5. The mould cavity 4 is below the arm 53and the levers 16 are kept one close to another, so that the rodsmounted on the levers 16 can receive a dose D and support it. The mouldcavity 4 is then moved towards the punch 5. In the meanwhile, anactuating arrangement which is not shown causes the levers 16 to open sothat the rods suddenly move away one from another and release the dose Dbetween the punch 5 and the mould unit 4, as shown in FIG. 47. The rodsare distanced apart one from another so that the mould cavity 4 can passtherebetween, as shown in FIG. 48, in order to reach the punch 5 andinteract with it so as to shape the dose D.

It is noted that the arm 53 integral with the carousel 2 disclosed inconnection with FIGS. 46 to 48 can be used in combination with anymutual arrangement of the punch and mould cavity.

According to an embodiment shown in FIG. 11, the levers supporting therods 11 are connected by a connecting rod 25. The latter is hinged at afirst end thereof to a first lever 16 a and, at a second end thereof, toa second lever 16 b. Both the first lever 16 a and the second lever 16 bcarry, at respective ends thereof, a corresponding rod 11 for supportingthe dose D.

An intermediate portion of the first lever 16 a is hinged at a point P1to a protrusion 26 fixed to the carousel 2. An end portion of the firstlever 16 a, opposite the end carrying the rod 11, is rotatably connectedto the connecting rod 25.

The second lever 16 b has a further end portion, opposite the endcarrying the rod 11, which is hinged at a point P2 to a furtherprotrusion 27 fixed relative to the carousel 2. An intermediate portionof the second lever 16 b is rotatably connected to the connecting rod25.

The first lever 16 a supports a cam follower 28, which engages a camtrack 29 by means of which the movement of the first lever 16 a can becontrolled. The first lever 16 a in turn actuates the second lever 16 bby means of the connecting rod 25. In this way, the rods 11 can be movedbetween the dose-receiving configuration and the dose-deliveringconfiguration.

The actuating system of the levers 16 a, 16 b disclosed with referenceto FIG. 11 can be associated to any one of the moulding unitarrangements previously described, i.e. having the punch below the mouldcavity or vice versa and having a movable punch and a fixed mould cavityor vice versa.

In FIGS. 49 and 50, a moulding unit 3 is shown in which the levers 16supporting the rods are actuated by a cam 519 having a first portion560, a second portion 561 adjacent to the first portion 560 and a thirdportion 562 adjacent to the second portion 561. The cam 519 is integralwith the carousel 2. The cam 519 extends along the direction F in whichthe mould cavity 4 is movable so that, when the mould cavity 4 movestowards the punch 5, the roller 22 interacts first with the firstportion 560, then with the second portion 561 and finally with the thirdportion 562. The first portion 560 protrudes from the carousel 2 to anextent that, when the roller 22 is in contact with the first portion560, the levers 16 are slightly open, i.e. they are slightly spacedapart one from another. In this position, which is shown in FIG. 49, adose D can be delivered onto the levers 16 and rest thereon. As themould cavity 4 moves towards the punch 5, the roller 22 moves away fromthe first portion 560 and starts interacting with the second portion561, which protrudes from the carousel 2 less than the first portion560. The levers 16 and the rods connected thereto thereby move closerone to another, so that the dose D, which simply rested on the rods, ispinched between the rods, as shown in FIG. 50. The rods can thus tightlygrip the dose D therebetween. The dose D is therefore prevented fromdetaching from the rods, even if centrifugal forces due to rotation ofthe carousel 2 act on the dose D.

As the mould cavity 4 moves still closer to the punch 5, the roller 22starts interacting with the third portion 562, which protrudes from thecarousel 2 more than the first portion 560 and the second portion 561.The third portion 562 causes the rods to suddenly move away one fromanother, thereby delivering the dose D to the mould cavity 4 or to thepunch 5, as already explained with reference to FIGS. 9 and 10.

It is noted that the cam arrangement shown in FIGS. 49 and 50 can alsobe used in a moulding unit in which the mould cavity is above the punch,or in which the mould cavity is stationary and the punch moves awayfrom, and towards to, the mould cavity, or in which both the punch andthe mould unity are movable. The direction F might also be non-vertical,e.g. horizontal. Furthermore, the cam might be mounted on a part of themoulding unit different from the carousel.

FIGS. 12 to 18 show an embodiment in which the rods 111 are movablebetween the dose-receiving configuration and the dose-deliveringconfiguration by oscillating around respective axes A1 extendingparallelly to the axis A of the carousel 2. Each rod 111 is fixed to arespective supporting bar 30 having a circular cross-section providedwith a flat surface 31. The flat surface 31 is shapingly coupled to anend portion of the respective rod 111 and prevents the rod 111 fromrotating with respect to the bar 30.

The bars 30 are connected to one other by means of a connecting device32, allowing the bars 30 to oscillate synchronously.

The connecting device 32 supports a cylinder 33 which engages a flat cam34.

As shown in FIG. 13, the flat cam 34 has a straight portion 35 and afurther straight portion 36, parallel to the straight portion 35 anddistanced apart therefrom. The straight portion 35 and the furtherstraight portion 36 are connected one to another by an oblique portion37.

When the cylinder 33 engages the straight portion 35, as shown in FIG.15, the rods 111 are in the dose-receiving configuration shown in FIG.14 and can support the dose D between the punch 5 and the mould cavity 4distanced apart one from the other, as shown in FIG. 16.

Subsequently, the mould cavity 4 is moved towards the punch 5, as shownin FIG. 17. The cylinder 33 thus engages first the oblique portion 37and then the further straight portion 36, as shown in FIG. 13. Thefurther straight portion 36 forces the cylinder 33 to oscillate theconnecting device 32 around the axis of the punch 5. The connectingdevice 32 oscillates in turn the bars 30, which causes the rods 111 toreach the dose-delivering configuration shown in FIG. 12. In thisconfiguration, the dose D is released between the mould cavity 4 and thepunch 5, which then interact to form the cap, as shown in FIG. 18.

It is observed that the rods 111 oscillatable around respective axesparallel to the axis of the carousel 2 may be used in combination withany mutual arrangement of the mould cavity and punch.

In the embodiment shown in FIG. 19, the rods 111 are actuated by a geardevice including a sector gear 38 integral with the connecting device32. As the carousel 2 rotates around the axis A, the sector gear 38cyclically interacts with a further sector gear 39 arranged in a fixedposition on the apparatus 1. The sector gear 38, when matching thefurther sector gear 39, moves the rods 111 between the dose-receivingconfiguration shown in FIG. 19 and the dose-delivering configuration.

It is stressed that the gear device disclosed in connection with FIG. 19can be used in combination with any mutual arrangement of the punch andmould cavity.

FIGS. 20 and 22 show a moulding unit 3 associated with a transferringwheel 40 rotatable about an axis perpendicular to the axis along whichthe mould cavity 4 is movable. The transferring wheel 40 is peripherallyprovided with a plurality of removal members 41, having a U-shapedcross-section.

As the transferring wheel 40 rotates around its respective axis, eachremoval member 41 interacts with an extrusion device 42 and removestherefrom a respective dose D. The removal member 41 delivers the dose Donto the rods 11 extending above a part of the moulding unit 3, namelyabove the mould cavity 4 in the particular case shown in FIG. 20.

The carousel 2 then moves the moulding unit 3 away from the transferringwheel 40 and, in the particular case shown in FIG. 21, the mould cavity4 can be actuated upwards towards the punch 5.

FIGS. 23 and 24 show a version in which the transferring wheel 40 isrotatable around an axis Z which is inclined of about 45° with respectto the axis of rotation of the carousel 2. Owing to this arrangement ofthe axis Z, it is possible to remove the dose D from an extrusion device42 having an extrusion axis parallel to the axis of the carousel 2 andto transfer the dose D onto the rods 11 of a moulding unit 3.

It is observed that the transferring wheel 40 may be used in combinationwith any mutual arrangement of the punch and moulding cavity previouslydisclosed.

In the embodiment shown in FIGS. 25 and 26, a transferring wheel 140,rotatable about an inclined axis Z1, is used to transfer a dose D1 ofplastics from an extrusion device 142 to a cap 43. The dose D1 insidethe cap 43 is then formed by a forming device not shown so as to obtaina sealing element in the cap 43. The sealing element avoids loss ofcontent from the container or bottle closed by the cap 43.

The transferring wheel 140 is peripherally provided with a plurality ofremoval members 141 having a leading, cutting edge 44 which detaches thedose D1 from the extrusion device 142. The doses D1 removed from theextrusion device 142 by subsequent removal members 141 are thentransferred onto respective caps 43 moved along an advancement directionF1 by a conveyor 45.

FIG. 27 shows a moulding unit 3 cooperating with a severing arrangementincluding a blade 46 mounted on a shaft 47 rotatable about an axis Z2.The blade 46 periodically interacts with an extruder mouth 48 and severstherefrom the dose D of plastics, which falls onto the underlying rods11.

The moulding unit 3 is then moved away from the extruder mouth 48, forexample by rotating around the axis of the carousel 2. The dose D isreleased between the punch 5 and the mould cavity 4 when the rods 11move from the dose-receiving configuration to the dose-deliveringconfiguration.

The blade 46 may also be associated to the moulding unit 3, as shown inFIG. 28. In this particular case, the blade 46 is connected to the mouldcavity 4 and moves synchronously with the rods 11 so as to periodicallyinteract with the extruder mouth 48 and sever therefrom the dose D.

The severing arrangement shown in FIGS. 27 and 28 is associated withrods 11 of the type shown in FIGS. 12 to 18. However, the severingarrangement might also be used in combination with other supportingarrangements and/or with different relative arrangements of the punchand the mould cavity.

FIGS. 29 to 31 disclose a severing arrangement according to anotherembodiment. In this embodiment, the mould cavity 4 is movable towards,and away from, the punch 5 which is located above the mould cavity 4. Aknife 49 having a substantially triangular shape is fixed to a side ofthe mould cavity 4.

When the mould cavity 4 is raised towards the punch 5, the knife 49interacts with an extruder mouth 48 a, feeding the plastics along ahorizontal extrusion axis. As shown in FIG. 29, the knife 49 severs fromthe extruder mouth 48 a the dose D, which then falls into the mouldcavity 4 due to gravity. The knife 49, owing to its triangular shape,also acts as a guide guiding the dose D towards the centre of the mouldcavity 4.

The mould cavity 4 finally reaches the closed position shown in FIG. 31,in which a cap is formed.

The severing arrangement allows the moulding apparatus to be simplified,because the extruder mouth can be located adjacent to the moulding unitsand there is no need to provide a transferring device for transferringthe doses from the extruder mouth to the moulding unit.

In the embodiment shown in FIGS. 29 to 31, the moulding apparatus can beeven simpler, since the supporting arrangement may be eliminated.

A severing arrangement of the type described above may also be used incombination with a horizontal moulding unit 3 a, as disclosed in FIGS.32 to 35.

The moulding unit 3 a includes a mould cavity 4 a, cooperating with apunch 5 a movable with respect to the mould cavity 4 a along ahorizontal direction H. The punch 5 a is provided, on a side thereoffacing upwards, with a knife 49 a. A cam 19 a is fixed to the punch 5 aat a side thereof opposite the side supporting the knife 49 a.

The mould cavity 4 a is provided with a pair of levers 216 hinged at apoint P on the lower part of the mould cavity 4 a. The levers 216 areL-shaped, and each of them includes a first arm 50 extending along thehorizontal direction H, and a second arm 51 perpendicular to the firstarm 50. The rods 11 a are supported at respective ends of the secondarms 51.

One of the levers 216 has an appendage 17 a supporting a roller 22 a. Anextruder mouth 48 b is arranged above the moulding unit 3 a.

As shown in FIG. 32, the extruder mouth 48 b is defined by terminalportions of a first conduit 307 and a second conduit 308 belonging tofirst and second extruders, not shown, processing a first plastics and asecond plastics.

In this way, outside the mouth 48 b the dose D comprises a first portion309 made from the first plastics and a second portion 310 made from thesecond plastics.

It is observed that while the first portion 309 faces the punch 5 a, thesecond portion 310 faces the mould cavity 4 a, in such a way that whenthe punch 5 a and the mould cavity 4 a are brought together to form ascrew cap 311 (shown in FIG. 41), the first portion 309 originates aninner wall 312 of the screw cap 311, while the second portion 310originates an outer wall 313 of the screw cap 311. Thus, it is possibleto manufacture a multi-layered screw cap 311, in which for example, theinner wall 312 is made from a material having peculiar barrierproperties and the outer wall 313 has peculiar mechanical, or chemical,or physical properties.

The moulding unit 3 a may also be used to manufacture items, for examplecaps, from a single plastics, as shown in FIGS. 33 to 35 in which thedose D is made of a single material.

When the punch 5 a moves towards the mould cavity 4 a, the knife 49 ainteracts with the extruder mouth 48 b and severs therefrom a dose D ofplastics. The dose D falls onto the underlying rods 11 a, which areclose to one another in the dose-receiving configuration. This can beseen in a side view in FIG. 32 and in a plan view in FIG. 33.

As the punch 5 a continues moving towards the mould cavity 4 a, theroller 22 a engages the cam 19 a, which causes the levers 216 to open byoscillating around the point P. The dose D remains therefore free in thespace between the punch 4 a and the mould cavity 5 a, as shown in FIG.34.

Subsequently, the punch 5 a moves closer to the mould cavity 4 a so asto compress the dose D and shape it as a cap, as shown in FIG. 35.

FIG. 36 shows a supporting arrangement provided with a pair of rods 211,each of which is provided with two adjacent curved portions 212 forreceiving two doses Da and Db therebetween.

The doses Da and Db can be of plastics having properties or coloursdiffering from each other and can be subsequently released between amould cavity and a punch to obtain a compression moulded articleprovided with a body of two different plastics.

The curved portions 212 allow the doses Da and Db to be properlypositioned on the rods 211; however, their presence is not essential andstraight rods might be used in place of the rods 211 shown in FIG. 36.The rods 211 and the curved portions 212, if any, may be of any porousmaterial and/or are optionally provided with holes 212 a orientedtowards the doses Da, Db to inject a fluid thereagainst and keep thesame under controlled conditions.

On the other hand, rods provided with curved portions might replace therods 11, 111, 11 a described with reference to the previous drawings.

As shown in FIG. 37, the doses Da, Db may also be supported by two pairsof rods 213, 214, which can be opened to release the doses, for examplewhen a mould cavity 314 is used having an elongated plan shape.

FIG. 38 shows an alternative embodiment in which rods 411 are providedfor supporting a pair of doses Da, Db. To this end, each rod 411 isprovided with two supporting plates 414 protruding towards correspondingsupporting plates fixed to the other rod. Each dose Da, Db is receivedon a pair of facing supporting plates 414 and rests thereon until it isdelivered to the mould cavity and/or to the punch.

If the doses Da and Db are of different materials, a hinge closure 315,as shown in FIG. 40, can be obtained in which a first closure portion316 is made from a particularly flexible material occupying a hingeregion 317, adjacently joined with a second closure portion 318 forfitting with a container not shown and made from a material compatiblewith the material from which the container is made in the fitting regiontherewith.

FIG. 39 shows a screw cap 250 whose bottom and side walls are made froma first material 251 and a second material 252, both of plastics, buthaving different colours.

It is also possible to use rods having curved portions like those shownin FIG. 36 or supporting plates like those shown in FIG. 38 to supportone single dose.

It is to be understood that in the above description the mould cavitiesand/or the punches may be driven by any suitable driving arrangement,such as pneumatic and/or hydraulic cylinders, or electro-magnetic linearactuators.

Furthermore, the mould cavity and the punch may have any desired shapeother than circular.

The supporting arrangement may also comprise heated rods, so that thetemperature of the dose may be accurately controlled. The rods may beheated, for example, by means of resistors, or by induction, or by meansof a jet of fluid, for example air.

Heating the supporting arrangement, or providing the same with tubularrods, or rods of porous material through which a pressurized fluid canbe injected, makes possible to ensure that detachment of the dose fromthe supporting arrangement occurs in any working conditions; in factsticking of the dose to the supporting arrangement is avoided.

The supporting arrangement may include rods that are coated with anonstick material, for example polytetrafluoroethylene (Teflon). Thenonstick material allows the dose to be easily detached from the rods,since it prevents the dose from sticking to the rods. Compressionmoulded items having a uniform appearance and uniform properties canthereby be obtained, because the portion of plastics which was incontact with the rods cannot be nearly distinguished in the finisheditem.

It is also to be understood that the features disclosed in thedescription of the Figures with reference to a specific embodiment maybe claimed also in connection with any other embodiments disclosed oreven per se.

1. Method for compression moulding of plastics items, comprising forming a dose of plastics in a moulding unit by bringing together a punch and a cavity mould along a path, wherein said punch is kept at a height which is not greater than the height of said cavity mould along said path, said method comprising providing a supporting arrangement extending externally of said cavity mould for supporting said dose, and further comprising before said bringing together, resting said dose on a pair of rods of said supporting arrangement, moving said rods close to one another so as to pinch said dose, and delivering said dose from said rods to said moulding unit, wherein between said resting and said moving said dose remains in contact with said rods.
 2. Method according to claim 1, and further comprising placing said punch under said cavity mould.
 3. Method according to claim 1, and further comprising placing said punch and said cavity mould on a common horizontal plane.
 4. Method according to claim 1, wherein said bringing together comprises moving said cavity mould between a closed position and an open position.
 5. Method according to claim 1, wherein said bringing together comprises moving said punch between a closed position and an open position.
 6. Method according to claim 1, and further comprising mounting said moulding unit on a rotating carousel.
 7. Method according to claim 1, and further comprising driving said supporting arrangement by a cam arrangement.
 8. Method according to claim 6, and further comprising driving said supporting arrangement by a cam arrangement.
 9. Method according to claim 7, and further comprising fixing said cam arrangement to said punch.
 10. Method according to claim 7, and further comprising fixing said cam arrangement to said cavity mould.
 11. Method according to claim 8, and further comprising fixing said cam arrangement to said to said carousel.
 12. Method according to claim 1, and further comprising providing said supporting arrangement with a pair of rods connected to a respective pair of levers hinged at a base body, each lever of said pair of levers being connected to the other lever of said pair of levers by a connection rod.
 13. Method according to claim 1, and further comprising oscillating said supporting arrangement by means of a gear device.
 14. Method according to claim 1, and further comprising providing said supporting arrangement with a supporting member, moving said supporting member between a dose-receiving configuration in which said supporting member is so arranged as to retain said dose and a dose-delivering configuration in which said supporting member is so arranged as to deliver said dose to said moulding unit.
 15. Method according to claim 7, and further comprising providing said supporting arrangement with a supporting member, moving said supporting member between a dose-receiving configuration in which said supporting member is so arranged as to retain said dose and a dose-delivering configuration in which said supporting member is so arranged as to deliver said dose to said moulding unit.
 16. Method according to claim 15, and further comprising providing said cam arrangement with a first portion for driving said supporting member and a further supporting member in said dose-receiving configuration and providing said cam arrangement with a second portion for driving said supporting member and said further supporting member in a dose-pinching configuration in which said dose is pinched between said supporting member and said further supporting member, said second portion being adjacent to said first portion.
 17. Method according to claim 15, and further comprising oscillating said supporting member parallel to an axis along which said punch and said cavity mould are movable.
 18. Method according to claim 15, and further comprising making said supporting member of porous material.
 19. Method according to claim 15, and further comprising providing said supporting member with a tubular supporting member having holes and injecting a fluid through said holes toward said dose.
 20. Method according to claim 15, and further comprising making said supporting member of thermally substantially non-conductive material.
 21. Method according to claim 15, and further comprising providing a substantially L-shaped supporting member.
 22. Method according to claim 15, and further comprising coating said supporting member with a substantially non stick material.
 23. Method according to claim 1, and further comprising mounting said supporting arrangement on said punch.
 24. Method according to claim 1, and further comprising mounting said supporting arrangement on said cavity mould.
 25. Method according to claim 1, and further comprising actuating said supporting arrangement along said path independently of said cavity mould and/or said punch.
 26. Method according to claim 1, and further comprising mounting said supporting arrangement on a carousel.
 27. Method according to claim 1, and further comprising positioning a dose-delivering mouth of an extruder between said punch and said cavity mould before bringing together said punch and said cavity mould to compress said dose.
 28. Method according to claim 27, and further comprising providing a severing arrangement co-operating with said dose-delivering mouth so as to sever said dose from said extruder.
 29. Method according to claim 28, and further comprising mounting said severing arrangement on said moulding unit.
 30. Method according to claim 28, and further comprising rotating said severing arrangement around a respective axis.
 31. Method according to claim 30, wherein said rotating comprises driving said severing arrangement by an independent motor unit.
 32. Method according to claim 25, and further comprising positioning a dose-delivering mouth of an extruder between said punch and said cavity mould before bringing together said punch and said cavity mould.
 33. Method according to claim 32, and further comprising providing a severing arrangement co-operating with said dose-delivering mouth so as to sever said dose from said extruder, a blade of said severing arrangement being connected to said supporting member.
 34. Method according to claim 28, and further comprising providing a knife of said severing arrangement and mounting said knife on said punch or on said cavity mould.
 35. Method according to claim 1, wherein before said bringing together said punch and said cavity mould said method further comprises placing a plurality of doses of plastics between said punch and said cavity mould, so as to interact when said punch and said cavity mould are brought together in a closed position.
 36. Method for compression moulding of plastics items, comprising forming a dose of plastics in a moulding unit by bringing together a punch and a cavity mould along a path, said method comprising providing a supporting arrangement for supporting said dose between said punch and said cavity mould, and further comprising before said bringing together, resting said dose on said supporting arrangement and delivering said dose from said supporting arrangement to said moulding unit, wherein, between said resting and said delivering, said dose remains in contact with said supporting arrangement, said method further comprising providing holes on a tubular supporting member of said supporting arrangement and injecting a fluid through said holes toward said dose.
 37. Method for compression moulding of plastics items, comprising forming a dose of plastics in a moulding unit by bringing together a punch and a cavity mould along a path, said method comprising before said bringing together, providing a dose-delivering mouth of an extruder between said punch and said cavity mould to deliver said dose.
 38. Method according to claim 37, and further comprising providing a severing arrangement co-operating with said dose-delivering mouth so as to sever said dose from said extruder.
 39. Method according to claim 38, and further comprising mounting said severing arrangement on said moulding unit.
 40. Method according to claim 39, and further comprising rotating said severing arrangement around a respective axis, said rotating comprises driving said severing arrangement by an independent motor unit.
 41. Method according to claim 38, and further comprising providing a blade of said severing arrangement connected to a supporting member of a supporting arrangement.
 42. Method according to claim 38, and further comprising providing a knife of said severing arrangement and mounting said knife on said punch or on said cavity mould.
 43. Method for compression moulding of plastics items, comprising forming a plurality of doses of plastics in a moulding unit by bringing together a punch and a cavity mould along a path, said method comprising receiving said plurality of doses of plastics therebetween before said bringing together.
 44. Method for compression moulding of plastics items, comprising forming a dose of plastics in a moulding unit by bringing together a punch and a cavity mould along a path, said method comprising providing a pair of rods for supporting said dose between said punch and said cavity mould, and actuating said pair of rods by a cam arrangement with a first portion for driving said rods in a dose-receiving configuration in which said dose is received above said rods and with a second portion for driving said rods in a dose-pinching configuration in which said dose is pinched between said rods, said second portion being adjacent to said first portion.
 45. Method according to claim 44, and further comprising arranging said first portion and said second portion in sequence along a direction, said punch and/or said cavity mould being movable along said direction to open or close said moulding unit.
 46. Method according to claim 44, and further comprising providing said cam arrangement with a third portion for driving said pair of rods in a dose-delivering position in which said dose is delivered between said punch and said cavity mould.
 47. Method according to claim 46, and further comprising arranging said first portion, said second portion and said third portion in sequence along said direction.
 48. Method according to claim 44, and further comprising providing a supporting arrangement for supporting said plurality of doses between said punch and said cavity mould in said open position.
 49. Method according to claim 48, and further comprising providing a pair of rods for supporting said plurality of doses.
 50. Method for compression moulding of plastics items, comprising forming a dose of plastic material in a moulding unit by bringing together a punch and a cavity mould, said method comprising providing a supporting arrangement for supporting said dose between said punch and said cavity mould, resting said dose on said supporting arrangement and delivering said dose from said supporting arrangement to said moulding unit, and further comprising before said bringing together, propelling said dose towards either said punch, or said cavity mould.
 51. Method according to claim 43, wherein the doses of plastics do not contact the punch or cavity mould when the punch and cavity mould initially begin to move together.
 52. Method according to claim 1, wherein the dose is held by the rods and is compression-formed into said plastic item after the dose is released by the rods and the punch and cavity mould are brought together. 